[Rd] Problem with accessibility in R 4.2.0 and 4.2.1.

[Tomas Kalibera]

Hi Andrew,

thanks a lot for your testing and I am looking forward to what you find 
out about the fixes in R-devel.

You asked about changes between 4.2.1 and 4.2.2 relevant to this. I 
don't think you overlooked anything, I looked now again at the source 
code diff and I didn't find anything relevant. The Rgui console was 
fixed to work with Alt+sequences (tilde on Italian keyboard). GraphApp 
was fixed to use the correct font charset for UTF-8 in dialog boxes. 
Search and replace was fixed in the script editor. Invalid write was 
fixed with printing very long lines.

None of those changes should impact the behavior of the caret in the 
console window. I would not be surprised if the behavior with the screen 
reader was unpredictable/random, certainly inconsequential to whether we 
had R 4.2.1 or 4.2.2. Hopefully the changes now in R-devel would make it 
more reliable. If not, we can try to improve it further.

Thanks for testing with JAWS, I am impressed it can get anything out 
from Rgui with the partial cursor. NVDA cannot, it allows navigating 
using left arrow/right arrow over the line (after focus out+in in R 
4.2.2), but it thinks that the characters on the line are all spaces.

In either case, I think using the partial cursor with screen readers 
doesn't make sense, it could only confuse the screen reader application. 
If some people preferred a wider cursor than "full", we could add a 
"wide full" cursor, that would be quite easy. If some people preferred 
less blinking or no blinking at all, they can already set that up 
system-wide in Windows for the "full" (or potential "wide full") cursor.

Cheers
Tomas

On 12/21/22 17:12, Andrew Hart wrote:
> HI Tomas,
>
> Thanks a lot for not letting this go. It is truly appreciated. I had 
> been using Rterm directly as Jonathan had suggested since we discussed 
> this a number of months ago on the R-devel list. However, about a week 
> and a half ago I accidentally launched Rgui for R 4.2.2 (which I 
> installed around the end of October) and was surprised when I could 
> actually  use it like I could use the pre-4.2 versions of R! I have 
> been using it for a little more than a week now and was intending to 
> write to you, but you beat me with this message.
> The accessibility of Rgui 4.2.2 seems very similar to R 4.1.2 (which I 
> still have on my system). In contrast, Rgui 4.2.1 is more or less 
> unusable. I was wanting to ask you if perhaps something got changed in 
> R 4.2.2? Nothing jumped out at me in the release notes, but I could 
> easily have overlooked something.
>
> After reading this message, I went and checked the cursor blink 
> setting in my 4.2.2 installation and it is indeed set to partial. 
> You're right in that occasionally JAWS loses the cursor and the 
> ability to read the R window. However, simply pressing the <enter> key 
> while Rgui has the focus fixes this. It seems that drawing a new 
> command prompt on a new line sets JAWS straight and I am able to keep 
> working. I haven't used 4.1.2 for a while, but I think it had the same 
> issue. I assumed that this was caused by moving from Windows 7 to 
> Windows 10, since I never encountered this kind of issue in windows 7. 
> I'll try out full cursor and see if that makes a difference in 4.2.2.
>
> Also, I'll download the development snapshot and try it out. I'll let 
> you know how I get on. Please excuse me if I don't get to it 
> immediately; things are a bit crazy at work at the moment and it is 
> that time of the year too!
>
> Cheers,
> Andrew.
>
> On 20/12/2022 19:33, Tomas Kalibera wrote:
>> Dear Andrew, Jonathan,
>>
>> I had a closer look and tried to improve accessibility in Rgui, 
>> please see below. I would be grateful for feedback.
>>
>> Rgui supports three cursor types, which can be selected via Edit/GUI 
>> preferences/Cursor blink.
>>
>> The default is "partial", but for screen readers, please use "full". 
>> You can change the selection in the menu and then "Save..." to save 
>> it into your Rconsole file. If you already have the file, the 
>> corresponding selection is "cursor_blink = Full".
>>
>> The "full" cursor is implemented as the standard Windows "caret" and 
>> this is what screen readers can see. Once you set this cursor as the 
>> default in your Rconsole file and re-start Rgui, but before you start 
>> using the console, please switch focus out and back in (e.g. press 
>> Alt+TAB twice). This helps NVDA detect the characters under the 
>> cursor in already released versions of R. Please start the screen 
>> reader before starting Rgui.
>>
>> I found that the "full" cursor implementation has a number of 
>> problems: in some situation it disappears when it shouldn't, in some 
>> the other way around. I thought this was confusing the screen reader, 
>> so I fixed most of these cases.
>>
>> However, the true cause was that Rgui didn't create the cursor right 
>> when it got focus the first time. Luckily NVDA is open-source, so one 
>> can read and modify the source code to find out. I've added a 
>> work-around to Rgui, which is used only with the "full" cursor, 
>> because the "partial" cursor confuses the screen reader too much to 
>> be usable, anyway. So, after this fix, one doesn't have to do that 
>> focus out+in trick.
>>
>> The improvements are in R-devel (revision 83482 or newer). I would be 
>> grateful if you could test it, so that it could be improved further 
>> (or reverted if it actually turned out worse). Particularly if you 
>> find a problem reproducible with NVDA, that should be something I 
>> could diagnose and improve, as I have the sources.
>>
>> I've been testing with NVDA and I'd be curious about the impact on JAWS.
>> Rgui doesn't work with Narrator.
>>
>> Thanks,
>> Tomas
>>
>> On 9/22/22 23:15, Andrew Hart via R-devel wrote:
>>>     On 22/09/2022 16:42, Toby Hocking wrote:
>>>> Another option is to use https://emacspeak.sourceforge.net/ 
>>>> <https://emacspeak.sourceforge.net/> (version of emacs editor/ide 
>>>> which can speak letters/words/lines -- has a blind maintainer) with 
>>>> https://ess.r-project.org/ <https://ess.r-project.org/> (interface 
>>>> for editing and running R code from within emacs)
>>>
>>> Thanks everyone for all the suggestions. Of course, the optimal 
>>> solution would be to figure out what is going on in Rgui, but, as is 
>>> always the case, the blind user use case is a fairly niche one. I 
>>> appreciate all the suggestions for finding an immediate solution to 
>>> my problem.
>>> I don't use any kind of IDE for working with R since I simply 
>>> haven't found one that is accessible or that i understand how to 
>>> use. There is a plug-in for the Eclipse IDE I installed a few years 
>>> ago, but I didn't understand the first thing about how it was to be 
>>> used. So I've just always worked with an editor open in one Window 
>>> and R in another,
>>> working interactively in R or bouncing over to the editor for more 
>>> complex things and sourcing code into R as necessary. However, I 
>>> only use the R console in Rgui. I went and had a look at Rterm, 
>>> which I have never used on Windows; I've only ever used it when 
>>> ssh-ing into Linux systems to use R. However, I've just found out 
>>> that Rterm does a number of fairly important things that probably 
>>> mean I can just use it instead of Rgui:
>>> 1. You can paste from the clipboard into the Rterm prompt;
>>> 2. It has a command history;
>>> 3. If you plot something, it opens a Window to draw the plot (I 
>>> never realised it could do this and had always assumed Rgui was 
>>> needed for this); and
>>> 4. It opens the HTML help if you ask for help on windows. I only 
>>> ever saw it display text help on Linux, but I was logged in 
>>> remotely. Text-based help is fine when ssh-ing into a machine, but 
>>> HTML help is much nicer to read and navigate.
>>>
>>> I think I'll just switch over to Rterm for a while, but I can also 
>>> check out ess, which I wasn't aware of.
>>>
>>> Thanks a lot,
>>> Andrew.
>>>
>>> ______________________________________________
>>> R-devel using r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>